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Abstract:

A system for producing oil and/or gas from an underground formation
comprising a first well above the formation; a second well above the
formation; the first well comprises a mechanism to inject a miscible
enhanced oil recovery formulation into the formation; the first well
comprises a seal comprising a fluorinated polymer, the seal adapted to
contain the miscible enhanced oil recovery formulation within a tubular;
and the second well comprises a mechanism to produce oil and/or gas from
the formation.

Claims:

1. A system for producing oil and/or gas from an underground formation
comprising: a first well above the formation; a second well above the
formation; the first well comprises a mechanism to inject a miscible
enhanced oil recovery formulation into the formation; the first well
comprises a seal comprising a fluorinated polymer, the seal adapted to
contain the miscible enhanced oil recovery formulation within a tubular;
and the second well comprises a mechanism to produce oil and/or gas from
the formation.

2. The system of claim 1, wherein the first well is at a distance of 10
meters to 1 kilometer from the second well.

3. The system of claim 1, wherein the underground formation is beneath a
body of water.

4. The system of claim 1, further comprising a mechanism for injecting an
immiscible enhanced oil recovery formulation into the formation after the
miscible enhanced oil recovery formulation has been released into the
formation.

6. The system of claim 5, wherein the miscible enhanced oil recovery
formulation is selected from the group consisting of a carbon disulfide
formulation, a carbon oxysulfide formulation, and mixtures thereof.

7. The system of claim 1, further comprising an immiscible enhanced oil
recovery formulation selected from the group consisting of water in gas
or liquid form, air, and mixtures thereof.

8. The system of claim 1, further comprising a miscible enhanced oil
recovery formulation comprising a carbon disulfide formulation.

9. The system of claim 1, further comprising a mechanism for producing a
carbon disulfide formulation.

10. The system of claim 1, wherein the underground formation comprises an
oil having a viscosity from 100 to 5,000,000 centipoise.

11. A method for producing oil and/or gas comprising: injecting a carbon
disulfide formulation into a formation from a first well; producing oil
and/or gas from the formation from a second well; and installing a seal
in the first well, the seal comprising a fluorinated polymer.

12. The method of claim 11, further comprising recovering carbon
disulfide formulation from the oil and/or gas and then injecting at least
a portion of the recovered carbon disulfide formulation into the
formation.

13. The method of claim 11, wherein injecting the carbon disulfide
formulation comprises injecting at least a portion of the carbon
disulfide formulation into the formation in a mixture with one or more of
hydrocarbons; sulfur compounds other than carbon disulfide; carbon
dioxide; carbon monoxide; or mixtures thereof.

14. The methods of claim 11, further comprising heating the carbon
disulfide formulation prior to injecting the carbon disulfide formulation
into the formation, or while within the formation.

15. The method of claim 11, wherein the carbon disulfide formulation is
injected at a pressure from 0 to 37,000 kilopascals above the initial
reservoir pressure, where the initial reservoir pressure is measured
prior to when carbon disulfide injection begins.

16. The method of claim 11, wherein the underground formation comprises a
permeability from 0.0001 to 15 Darcies.

17. The method of claim 11, wherein any oil, as present in the
underground formation prior to the injecting the carbon disulfide
formulation, has a sulfur content from 0.5% to 5%.

18. The method of claim 11, further comprising converting at least a
portion of the recovered oil and/or gas into a transportation fuel.

19. The method of claim 11, wherein the fluorinated polymer is at least
40% fluorinated.

20. The method of claim 11, wherein the fluorinated polymer is at least
80% fluorinated.

21. The method of claim 11, wherein the fluorinated polymer is selected
from the group consisting of polytetrafluoroethylene, fluorinated
ethylene-propylene copolymers, fluoroelastomers, copolymers of vinylidene
fluoride and hexafluoropropylene, and perfluoroelastomers.

Description:

[0002] Enhanced Oil Recovery (EOR) may be used to increase oil recovery in
fields worldwide. There are three main types of EOR, thermal,
chemical/polymer and gas injection, which may be used to increase oil
recovery from a reservoir, beyond what can be achieved by conventional
means--possibly extending the life of a field and boosting the oil
recovery factor.

[0003] Thermal enhanced recovery works by adding heat to the reservoir.
The most widely practiced form is a steamdrive, which reduces oil
viscosity so that it can flow to the producing wells. Chemical flooding
increases recovery by reducing the capillary forces that trap residual
oil. Polymer flooding improves the sweep efficiency of injected water.
Miscible injection works in a similar way to chemical flooding. By
injecting a fluid that is miscible with the oil, trapped residual oil can
be recovered.

[0004] Referring to FIG. 1, there is illustrated prior art system 100.
System 100 includes underground formation 102, underground formation 104,
underground formation 106, and underground formation 108. Production
facility 110 is provided at the surface. Well 112 traverses formations
102 and 104, and terminates in formation 106. The portion of formation
106 is shown at 114. Oil and gas are produced from formation 106 through
well 112, to production facility 110. Gas and liquid are separated from
each other, gas is stored in gas storage 116 and liquid is stored in
liquid storage 118.

[0005] U.S. Pat. No. 4,026,583 discloses an oil well pipe incorporating a
corrosion-resistant, metallic liner which is intimately metallurgically
bonded to the pipe bore. A non-metallic annular seal may be provided in
an annular groove to seal off between the tapered interfitting surfaces
between the liner box and pin sections; for example, the seal may consist
of polytetrafluoroethylene material, as for example TEFLON or VITON, and
may comprise an O-ring having a radial thickness of between 0.025 and
0.225 inches. U.S. Pat. No. 4,026,583 is herein incorporated by reference
in its entirety.

[0006] U.S. Patent Application Publication Number 2006/0048941 discloses
an apparatus and method for controlling and/or minimizing the formation
or accumulation of unwanted deposits on the inside of fluid flow paths by
employing at various locations along the path an assembly of permanent
magnets oriented such that the fluid flow is preferably from the North
magnetic pole to the South magnetic pole. Suitable materials for use as
seals include but are not limited to fluorocarbon rubber (FKM)-type seals
and O-rings, including KEL-F and FLUOREL (both available from 3M, St.
Paul, Minn.), VITON and KALREZ (both available from E.I. DuPont de
Nemours Co.); chlorosulfonated polyethylenes, such as HYPHALON (available
from DuPont Dow Elastomers); PTFE (TEFLON) and filled PTFE such as
FLUOROSINT (available from Quadrant DSM Engineering Plastic Products,
Reading, Pa.); copolymers of butadiene and acrylonitrile, known as Buna-N
(nitrile; NBR), such as HYVCAR (available from Goodrich Chemical Co.);
and silicone or silicone rubber. Typically, seals are fluorocarbon
rubber-type seals, such as VITON. U.S. Patent Application Publication
Number 2006/0048941 is herein incorporated by reference in its entirety.

[0007] Co-pending U.S. Patent Application Publication Number 2006/0254769,
published Nov. 16, 2006, and having attorney docket number TH2616,
discloses a system including a mechanism for recovering oil and/or gas
from an underground formation, the oil and/or gas comprising one or more
sulfur compounds; a mechanism for converting at least a portion of the
sulfur compounds from the recovered oil and/or gas into a carbon
disulfide formulation; and a mechanism for releasing at least a portion
of the carbon disulfide formulation into a formation. U.S. Patent
Application Publication Number 2006/0254769 is herein incorporated by
reference in its entirety.

[0008] There is a need in the art for improved systems and methods for
enhanced oil recovery. There is a further need in the art for improved
systems and methods for enhanced oil recovery using a solvent, for
example through viscosity reduction, chemical effects, and miscible
flooding. There is a further need in the art for improved systems and
methods for solvent miscible flooding. There is a further need in the art
for improved systems and methods for transporting a miscible solvent in a
pipe during an enhanced oil recovery operation. There is a need in the
art for improved seals to be used with a miscible solvent in a pipe
during an enhanced oil recovery operation.

SUMMARY OF THE INVENTION

[0009] In one aspect, the invention provides a system for producing oil
and/or gas from an underground formation comprising a first well above
the formation; a second well above the formation; the first well
comprises a mechanism to inject a miscible enhanced oil recovery
formulation into the formation; the first well comprises a seal
comprising a fluorinated polymer, the seal adapted to contain the
miscible enhanced oil recovery formulation within a tubular; and the
second well comprises a mechanism to produce oil and/or gas from the
formation.

[0010] In another aspect, the invention provides a method for producing
oil and/or gas comprising injecting a carbon disulfide formulation into a
formation from a first well; producing oil and/or gas from the formation
from a second well; and installing a seal in the first well, the seal
comprising a fluorinated polymer.

[0011] Advantages of the invention include one or more of the following:

[0012] Improved systems and methods for enhanced recovery of hydrocarbons
from a formation with a solvent.

[0013] Improved systems and methods for enhanced recovery of hydrocarbons
from a formation with a fluid containing a miscible solvent.

[0014] Improved systems and methods for secondary recovery of
hydrocarbons.

[0015] Improved systems and methods for enhanced oil recovery.

[0016] Improved systems and methods for enhanced oil recovery using a
miscible solvent.

[0017] Improved systems and methods for enhanced oil recovery using a
compound which may be miscible with oil in place.

[0018] Improved systems and methods for transporting and/or containing a
compound in a pipe which may be miscible with oil in place.

[0019] Improved systems and methods for sealing a compound in a pipe which
may be miscible with oil in place.

[0027] Referring now to FIG. 2, in some embodiments system 200 is
illustrated. System 200 includes underground formation 202, underground
formation 204, underground formation 206, and underground formation 208.
Facility 210 may be provided at the surface. Well 212 traverses
formations 202 and 204, and has multiple openings in formation 206.
Portions 214 of formation 206 may be optionally fractured and/or
perforated. During primary production, oil and gas from formation 206 may
be produced into portions 214, into well 212, and travels up to facility
210. Facility 210 then separates gas, which may be sent to gas processing
216, and liquid, which may be sent to liquid storage 218. Facility 210
also includes miscible enhanced oil recovery formulation storage 230.

[0028] As shown in FIG. 2, miscible enhanced oil recovery formulation may
be pumped down well 212 that is shown by the down arrow and pumped into
formation 206. Miscible enhanced oil recovery formulation and oil and/or
gas may be then produced back up well 212 to facility 210, as shown by up
arrow. Facility 210 may be adapted to separate and/or recycle miscible
enhanced oil recovery formulation, for example by boiling the
formulation, condensing it or filtering or reacting it, then re-injecting
the formulation into well 212.

[0029] In some embodiments, miscible enhanced oil recovery formulation may
be pumped into formation 206 below the fracture pressure of the
formation, for example from about 40% to about 90% of the fracture
pressure.

[0030] The recovery of oil and/or gas with one or more wells (such as well
212) from underground formation 206 may be accomplished by any known
method. Suitable methods include subsea production, surface production,
primary, secondary, or tertiary production. The selection of the method
used to recover the oil and/or gas from underground formation 206 is not
critical.

[0031] FIGS. 3a and 3b:

[0032] Referring now to FIGS. 3a and 3b, in some embodiments of the
invention, system 200 is illustrated. System 200 includes underground
formation 202, underground formation 204, underground formation 206, and
underground formation 208. Facility 210 may be provided at the surface.
Well 212 traverses formations 202 and 204, and has openings in formation
206. Portions 214 of formation 206 may be optionally fractured and/or
perforated. During primary production, oil and gas from formation 206 may
be produced into portions 214, into well 212, and travels up to facility
210. Facility 210 then separates gas, which may be sent to gas processing
216, and liquid, which may be sent to liquid storage 218. Facility 210
also includes miscible enhanced oil recovery formulation storage 230.

[0033] As shown in FIG. 3a, miscible enhanced oil recovery formulation may
be pumped down well 212 that is shown by the down arrow and pumped into
formation 206. Miscible enhanced oil recovery formulation may be left to
soak in formation for a period of time from about 1 hour to about 15
days, for example from about 5 to about 50 hours.

[0034] After the soaking period, as shown in FIG. 3b, miscible enhanced
oil recovery formulation and oil and/or gas may be then produced back up
well 212 to facility 210. Facility 210 may be adapted to separate and/or
recycle miscible enhanced oil recovery formulation, for example by
boiling the formulation, condensing it or filtering or reacting it, then
re-injecting the formulation into well 212, for example by repeating the
soaking cycle shown in FIGS. 3a and 3b from about 2 to about 5 times.

[0035] In some embodiments, miscible enhanced oil recovery formulation may
be pumped into formation 206 below the fracture pressure of the
formation, for example from about 40% to about 90% of the fracture
pressure.

[0036] FIG. 3c:

[0037] Referring now to FIG. 3c, in some embodiments of the invention,
system 300 is illustrated. System 300 includes underground formation 302,
formation 304, formation 306, and formation 308. Production facility 310
may be provided at the surface. Well 312 traverses formation 302 and 304
has openings at formation 306.

[0038] Portions of formation 314 may be optionally fractured and/or
perforated. As oil and gas is produced from formation 306 it enters
portions 314, and travels up well 312 to production facility 310. Gas and
liquid may be separated, and gas may be sent to gas storage 316, and
liquid may be sent to liquid storage 318. Production facility 310 may be
able to produce and/or store miscible enhanced oil recovery formulation,
which may be produced and stored in production/storage 330. Hydrogen
sulfide and/or other sulfur containing compounds from well 312 may be
sent to miscible enhanced oil recovery formulation production/storage
330. Miscible enhanced oil recovery formulation may be pumped down well
332, to portions 334 of formation 306. Miscible enhanced oil recovery
formulation traverses formation 306 to aid in the production of oil and
gas, and then the miscible enhanced oil recovery formulation, oil and/or
gas may all be produced to well 312, to production facility 310. Miscible
enhanced oil recovery formulation may then be recycled, for example by
boiling the formulation, condensing it or filtering or reacting it, then
re-injecting the formulation into well 332.

[0039] In some embodiments, a quantity of miscible enhanced oil recovery
formulation or miscible enhanced oil recovery formulation mixed with
other components may be injected into well 332, followed by another
component to force miscible enhanced oil recovery formulation or miscible
enhanced oil recovery formulation mixed with other components across
formation 306, for example air; water in gas or liquid form; water mixed
with one or more salts, polymers, and/or surfactants; carbon dioxide;
other gases; other liquids; and/or mixtures thereof.

[0041] Referring now to FIG. 4, in some embodiments of the invention,
system 700 is illustrated. System 700 includes underground formation 702,
formation 704, formation 706, and formation 708; and underground
formation 802, formation 804, formation 806, and formation 808.
Production facility 710 is provided at the surface. Well 712 traverses
formation 702 and 704 has openings at formation 706. Portions of
formation 714 may be optionally fractured and/or perforated. As oil and
gas is produced from formation 706 it enters portions 714, and travels up
well 712 to production facility 710. Gas and liquid may be separated, and
gas may be sent to gas storage 716, and liquid may be sent to liquid
storage 718. Production facility 710 is able to produce carbon disulfide
and/or carbon oxysulfide formulation, which may be produced and stored in
carbon disulfide formulation production 730. Hydrogen sulfide and/or
other sulfur containing compounds from well 712 may be sent to carbon
disulfide formulation production 730. Carbon disulfide formulation is
transported to well 732 by pipe 734 and pumped down well 732, to
formation 806. Carbon disulfide formulation may be used in formation 806
to aid in the production of oil and gas from formation 806.

[0042] Well 732 is separated from well 712 by a distance d 740. In some
embodiments, distance d 740 is from about 1 to about 1000 kilometers, for
example from about 5 to about 250 kilometers, or for example from about
10 to about 100 kilometers, or for example about 50 to 75 kilometers.

[0043] FIGS. 5a & 5b:

[0044] Referring now to FIG. 5a, a tubular 900 is illustrated traversing
formations 802 and 804, and ending in formation 806. Tubular 900 may be
used as an observation well, a peripheral containment well, an injection
well, and/or a production well.

[0045] Referring now to FIG. 5b, tubular 900 is shown in more detail.
Tubular 900 includes internal tubular 902 located within external tubular
904. Internal tubular 902 is made up of multiple sections, connected at
joints 908. External tubular 904 is made up of multiple sections,
connected at joints 910. Packer 906 may be provided between the exterior
of tubular 902 and the interior of tubular 904. Packer may seal off an
upper annular space between the exterior of tubular 902 and the interior
of tubular 904 from a lower annular space, for example a production or
injection zone.

[0046] Packer 906 may have one or more sealing elements on its interior
surface adjacent tubular 902 and/or one or more sealing elements on its
exterior surface adjacent tubular 904.

[0048] Referring now to FIG. 6, tubular system 1000 with threaded tubular
connection 1008 is illustrated. Tubular 1030 having pin end 1012 is
threadingly engaged with tubular 1020 having box end 1010. Pin end 1012
is the male connection which fits within box end 1010 which is the female
connection.

[0049] One or more seals 1014 and/or 1016 may be provided adjacent the
threaded connections. Seals 1014 and/or 1016 may be o-rings or other seal
configurations as are known in the art. Seals 1014 and/or 1016 may be
fitted into grooves on tubulars 1020 and/or 1030. Seals 1014 and/or 1016
may be used to provide a seal between an interior and exterior of
tubulars 1020 and 1030, for example to contain fluids within tubulars
1020 and 1030 and/or to keep fluids out of tubulars 1020 and 1030.
Tubular system 1000 may be representative of one or more parts of well
212, 312, 332, 712, 732, and/or tubular 900, 902, and/or 904.

[0050] Seal Materials:

[0051] In some embodiments, seals 1014 and/or 1016 and packer 906 may be
made of fluorinated polymers such as PTFE (polytetrafluoroethylene),
fluorinated ethylene-propylene copolymers, commercially available as
Teflon® from Du Pont; fluoroelastomers such as a copolymer of
vinylidene fluoride and hexafluoropropylene, commercially available as
Viton® from Du Pont, for example Viton A; or perfluoroelastomers such
as a copolymer of vinylidene fluoride and hexafluoropropylene,
commercially available as Kalrez® from Du Pont, for example Kalrez
AS-568 3018-1.

[0052] In some embodiments, seals 1014 and/or 1016 and packer 906 may be
made of fluorocarbon polymers, perfluorocarbon polymers,
fluoroelastomers, or perfluoroelastomers.

[0053] In some embodiments, seals 1014 and/or 1016 and packer 906 may be
made of a fluorinated polymer, where at least about 25% of the hydrogens
attached to a carbon have been replaced with a fluorine or chlorine, for
example replacing at least about 50% of the hydrogens, at least about 75%
of the hydrogens, or at least about 90% of the hydrogens.

ALTERNATIVE EMBODIMENTS

[0054] In some embodiments, oil and/or gas may be recovered from a
formation into a well, and flow through the well and flowline to a
facility. In some embodiments, enhanced oil recovery, with the use of an
agent for example steam, water, a surfactant, a polymer flood, and/or a
miscible agent such as a carbon disulfide formulation, a carbon
oxysulfide formulation, and/or carbon dioxide, may be used to increase
the flow of oil and/or gas from the formation.

[0055] In some embodiments, oil and/or gas recovered from a formation may
include a sulfur compound. The sulfur compound may include hydrogen
sulfide, mercaptans, sulfides and disulfides other than hydrogen
disulfide, or heterocyclic sulfur compounds for example thiophenes,
benzothiophenes, or substituted and condensed ring dibenzothiophenes, or
mixtures thereof.

[0056] In some embodiments, a sulfur compound from the formation may be
converted into a carbon disulfide formulation or a carbon oxysulfide
formulation. The conversion of at least a portion of the sulfur compound
into a carbon disulfide formulation may be accomplished by any known
method. Suitable methods may include oxidation reaction of the sulfur
compound to sulfur and/or sulfur dioxides, and by reaction of sulfur
and/or sulfur dioxide with carbon and/or a carbon containing compound to
form the carbon disulfide formulation. The selection of the method used
to convert at least a portion of the sulfur compound into a carbon
disulfide formulation is not critical.

[0057] In some embodiments, a suitable miscible enhanced oil recovery
agent may be a carbon disulfide formulation. The carbon disulfide
formulation may include carbon disulfide and/or carbon disulfide
derivatives for example, thiocarbonates, xanthates and mixtures thereof;
and optionally one or more of the following: hydrogen sulfide, sulfur,
carbon dioxide, hydrocarbons, and mixtures thereof.

[0058] In some embodiments, a suitable method of producing a carbon
disulfide formulation is disclosed in copending U.S. patent application
Ser. No. 11/409,436, filed on Apr. 19, 2006, having attorney docket
number TH2616. U.S. patent application Ser. No. 11/409,436 is herein
incorporated by reference in its entirety.

[0059] In some embodiments, suitable miscible enhanced oil recovery agents
include carbon disulfide, carbon oxysulfide, hydrogen sulfide, carbon
dioxide, octane, pentane, LPG, C2-C6 aliphatic hydrocarbons, nitrogen,
diesel, mineral spirits, naptha solvent, asphalt solvent, kerosene,
acetone, xylene, trichloroethane, or mixtures of two or more of the
preceding, or other miscible enhanced oil recovery agents as are known in
the art. In some embodiments, suitable miscible enhanced oil recovery
agents are first contact miscible or multiple contact miscible with oil
in the formation.

[0060] In some embodiments, suitable immiscible enhanced oil recovery
agents include water in gas or liquid form, air, mixtures of two or more
of the preceding, or other immiscible enhanced oil recovery agents as are
known in the art. In some embodiments, suitable immiscible enhanced oil
recovery agents are not first contact miscible or multiple contact
miscible with oil in the formation.

[0061] In some embodiments, immiscible and/or miscible enhanced oil
recovery agents injected into the formation may be recovered from the
produced oil and/or gas and re-injected into the formation.

[0062] In some embodiments, oil as present in the formation prior to the
injection of any enhanced oil recovery agents has a viscosity of at least
about 100 centipoise, or at least about 500 centipoise, or at least about
1000 centipoise, or at least about 2000 centipoise, or at least about
5000 centipoise, or at least about 10,000 centipoise. In some
embodiments, oil as present in the formation prior to the injection of
any enhanced oil recovery agents has a viscosity of up to about 5,000,000
centipoise, or up to about 2,000,000 centipoise, or up to about 1,000,000
centipoise, or up to about 500,000 centipoise.

[0063] Releasing at least a portion of the miscible enhanced oil recovery
agent and/or other liquids and/or gases may be accomplished by any known
method. One suitable method is injecting the miscible enhanced oil
recovery formulation into a single conduit in a single well, allowing
carbon disulfide formulation to soak, and then pumping out at least a
portion of the carbon disulfide formulation with gas and/or liquids.
Another suitable method is injecting the miscible enhanced oil recovery
formulation into a first well, and pumping out at least a portion of the
miscible enhanced oil recovery formulation with gas and/or liquids
through a second well. The selection of the method used to inject at
least a portion of the miscible enhanced oil recovery formulation and/or
other liquids and/or gases is not critical.

[0064] In some embodiments, the miscible enhanced oil recovery formulation
and/or other liquids and/or gases may be pumped into a formation at a
pressure up to the fracture pressure of the formation.

[0065] In some embodiments, the miscible enhanced oil recovery formulation
may be mixed in with oil and/or gas in a formation to form a mixture
which may be recovered from a well. In some embodiments, a quantity of
the miscible enhanced oil recovery formulation may be injected into a
well, followed by another component to force carbon the formulation
across the formation. For example air, water in liquid or vapor form,
carbon dioxide, other gases, other liquids, and/or mixtures thereof may
be used to force the miscible enhanced oil recovery formulation across
the formation.

[0066] In some embodiments, the miscible enhanced oil recovery formulation
may be heated prior to being injected into the formation to lower the
viscosity of fluids in the formation, for example heavy oils, paraffins,
asphaltenes, etc.

[0067] In some embodiments, the miscible enhanced oil recovery formulation
may be heated and/or boiled while within the formation, with the use of a
heated fluid or a heater, to lower the viscosity of fluids in the
formation. In some embodiments, heated water and/or steam may be used to
heat and/or vaporize the miscible enhanced oil recovery formulation in
the formation.

[0068] In some embodiments, the miscible enhanced oil recovery formulation
may be heated and/or boiled while within the formation, with the use of a
heater. One suitable heater is disclosed in copending U.S. patent
application Ser. No. 10/693,816, filed on Oct. 24, 2003, and having
attorney docket number TH2557. U.S. patent application Ser. No.
10/693,816 is herein incorporated by reference in its entirety.

[0069] In some embodiments, oil and/or gas produced may be transported to
a refinery and/or a treatment facility. The oil and/or gas may be
processed to produced to produce commercial products such as
transportation fuels such as gasoline and diesel, heating fuel,
lubricants, chemicals, and/or polymers. Processing may include distilling
and/or fractionally distilling the oil and/or gas to produce one or more
distillate fractions. In some embodiments, the oil and/or gas, and/or the
one or more distillate fractions may be subjected to a process of one or
more of the following: catalytic cracking, hydrocracking, hydrotreating,
coking, thermal cracking, distilling, reforming, polymerization,
isomerization, alkylation, blending, and dewaxing.

ILLUSTRATIVE EMBODIMENTS

[0070] In one embodiment of the invention, there is disclosed a system for
producing oil and/or gas from an underground formation comprising a first
well above the formation; a second well above the formation; the first
well comprises a mechanism to inject a miscible enhanced oil recovery
formulation into the formation; the first well comprises a seal
comprising a fluorinated polymer, the seal adapted to contain the
miscible enhanced oil recovery formulation within a tubular; and the
second well comprises a mechanism to produce oil and/or gas from the
formation. In some embodiments, the first well is at a distance of 10
meters to 1 kilometer from the second well. In some embodiments, the
underground formation is beneath a body of water. In some embodiments,
the system also includes a mechanism for injecting an immiscible enhanced
oil recovery formulation into the formation, after the miscible enhanced
oil recovery formulation has been released into the formation. In some
embodiments, the system also includes a miscible enhanced oil recovery
formulation selected from the group consisting of a carbon disulfide
formulation, a carbon oxysulfide formulation, hydrogen sulfide, carbon
dioxide, octane, pentane, LPG, C2-C6 aliphatic hydrocarbons, nitrogen,
diesel, mineral spirits, naptha solvent, asphalt solvent, kerosene,
acetone, xylene, trichloroethane, and mixtures thereof. In some
embodiments, the miscible enhanced oil recovery formulation comprises a
carbon disulfide formulation, a carbon oxysulfide formulation, or
mixtures thereof. In some embodiments, the system also includes an
immiscible enhanced oil recovery formulation selected from the group
consisting of water in gas or liquid form, air, and mixtures thereof. In
some embodiments, the system also includes a miscible enhanced oil
recovery formulation comprising a carbon disulfide formulation. In some
embodiments, the system also includes a mechanism for producing a carbon
disulfide formulation. In some embodiments, the underground formation
comprises an oil having a viscosity from 100 to 5,000,000 centipoise.

[0071] In one embodiment of the invention, there is disclosed a method for
producing oil and/or gas comprising injecting a carbon disulfide
formulation into a formation from a first well; producing oil and/or gas
from the formation from a second well; and installing a seal in the first
well, the seal comprising a fluorinated polymer. In some embodiments, the
method also includes recovering carbon disulfide formulation from the oil
and/or gas, if present, and then injecting at least a portion of the
recovered carbon disulfide formulation into the formation. In some
embodiments, injecting the carbon disulfide formulation comprises
injecting at least a portion of the carbon disulfide formulation into the
formation in a mixture with one or more of hydrocarbons; sulfur compounds
other than carbon disulfide; carbon dioxide; carbon monoxide; or mixtures
thereof. In some embodiments, the method also includes heating the carbon
disulfide formulation prior to injecting the carbon disulfide formulation
into the formation, or while within the formation. In some embodiments,
the carbon disulfide formulation is injected at a pressure from 0 to
37,000 kilopascals above the initial reservoir pressure, measured prior
to when carbon disulfide injection begins. In some embodiments, the
underground formation comprises a permeability from 0.0001 to 15 Darcies,
for example a permeability from 0.001 to 1 Darcy. In some embodiments,
any oil, as present in the underground formation prior to the injecting
the carbon disulfide formulation, has a sulfur content from 0.5% to 5%,
for example from 1% to 3%. In some embodiments, the method also includes
converting at least a portion of the recovered oil and/or gas into a
material selected from the group consisting of transportation fuels such
as gasoline and diesel, heating fuel, lubricants, chemicals, and/or
polymers. In some embodiments, the fluorinated polymer is at least 40%
fluorinated. In some embodiments, the fluorinated polymer is at least 80%
fluorinated. In some embodiments, the fluorinated polymer is selected
from the group consisting of polytetrafluoroethylene, fluorinated
ethylene-propylene copolymers, fluoroelastomers, copolymers of vinylidene
fluoride and hexafluoropropylene, or perfluoroelastomers.

[0072] Those of skill in the art will appreciate that many modifications
and variations are possible in terms of the disclosed embodiments of the
invention, configurations, materials and methods without departing from
their spirit and scope. Accordingly, the scope of the claims appended
hereafter and their functional equivalents should not be limited by
particular embodiments described and illustrated herein, as these are
merely exemplary in nature.